Originally Posted by Mike1

Most road cars will no no longer be running exactly as per factory these days ( or will be on very tired OE springs/dampers/bushes and different tyres/wheels ) so it's a bit of a moot point nowadays.

The 3 door was developed to be a competition car - very fast responses almost to the point of being regarded as 'twitchy' for a road car. That was a common criticism of the 3-doors on the press launch and Ford reportedly made some changes to the power steering, front bush materials and settings etc to make them less 'nervous' for the average driver on heavily cambered/longitudinally ridged roads.

The later H14 ARB added about a degree of extra caster over the H13 arb as fitted to the very first 3-door cars. Some original customers had the H14 retro-fitted by the dealer under recall if they complained and I think the last of the 3-doors and the RS500s had the H14 type anyway as did the Sapphires. Think they were all 28 mm at the front on 2wders though.

When the Sapphire was released it had a 2mm thicker rear ARB ( 16mm over 14mm ). The shell was stiffer, spring rates went from 106lb/in to 118lb/in at the front and from 263 to 286lb/in at the rear. The damper rates were softer in bump but stiffer in rebound on the 4-door. Front camber was slightly more negative and the big change was the front steering knuckle where the roll centre was dropped from 144mm to 70mm above the floor.

All these changes helped rid the Sapphire of the corkscrewing motion that a standard 3-door can get in a long fast bend sometimes.

The sapphire was said to be a less 'nervous', more stable car when really pushed and this is oftten why they were timed very slightly faster round a track. On the flipside, keen drivers said the 4-door had lost some of the razor sharp turn in the 3-doors were sometimes criticized for.

Swings and roundabouts really but there's loads of bits you can get/do to make the cars handle 'better' for your use so I doubt there's much in it these days unless you wanted to compare stock factory cars ( and I doubt the OE tyres are still available anyway )